The organization said it will spend $100,000 over two days on broadcast TV and online ads urging Peters to reconsider his support for the international agreement.

“This deal with Iran is a historic mistake that could have cataclysmic consequences for America and our allies,” said Mike Shields, president of the group. “Yet despite all the bipartisan warnings, Scott Peters has shown he’s willing to sacrifice sanity and our safety by supporting a deal that paves the way for a nuclear Iran.”

The ad campaign also targets Representatives Rick Nolan of Minnesota, Debbie Wasserman Schultz of Florida, Louise Slaughter of New York and Pete Aguilar, who represents parts of the Inland Empire. A total of $250,000 is being spent.

Peters announced last month that after careful study of the options, he had concluded that the deal “is our best tool to prevent Iran from building a nuclear weapon for at least the next 15 years.”

The agreement with Iran negotiated by the United States, the United Kingdom, France, China, Russia and Germany ends economic sanctions against the Islamic republic in exchange for measures that prevent it from acquiring a nuclear weapon.

President Obama has argued that war is the only alternative to the deal, but it has drawn sharp criticism from Republican lawmakers and the state of Israel, and has divided the American Jewish community. Congress is expected to reject the deal, but would likely not have enough votes to override a presidential veto.